National Certified Addiction Counselor, Level I (NCAC I) Practice Exam

Which components make up the peripheral nervous system (PNS)?

1. Brain and spinal cord

2. Motor pathways and sensory pathways

3. Sympathetic and parasympathetic pathways

4. Cranial and spinal nerves

The correct answer is: Motor pathways and sensory pathways

The peripheral nervous system (PNS) is fundamentally composed of cranial and spinal nerves that branch out from the central nervous system (CNS), which includes the brain and spinal cord. The PNS is responsible for transmitting sensory information to the CNS and relaying motor commands from the CNS to the muscles and glands throughout the body. While motor pathways and sensory pathways are functional components within the PNS, they are not the defining structural components. The motor pathways are responsible for carrying signals from the CNS to the muscles, facilitating movement, while sensory pathways carry signals from sensory receptors to the CNS, enabling the perception of the environment. Cranial and spinal nerves, as structural components of the PNS, serve critical roles in connecting the CNS to the limbs and organs. Both sympathetic and parasympathetic pathways refer specifically to the autonomic nervous system, which is a subdivision of the PNS but does not encompass its entirety. Thus, recognizing cranial and spinal nerves as the primary components of the PNS provides a clearer and more accurate depiction of its anatomical structure.